net.rim.blackberry.api.bbm.platform.io
Interface BBMPlatformChannel

When a channel is created, the user can invite one or more BBM contacts to interact.
also, any participant can further invite their BBM contacts to join to the channel.
Note that a person in a channel is visible and available to only those whom this person invited or who invited this person,
which is different from BBMPlatformSession.
For example, if user_A invited user_B to a channel and user_B joined, then user_B invited user_C to join to the same channel and user_C joined.
In this case, user_A sees user_B only and thus can share data with user_B only. So does user_C since he/she was invited by user_B.
User_B can see both user_A and user_C in this channel and thus can share data with both of them.
But user_A and user_C are not visible to each other and thus cannot share data with each other.

destroy

public void destroy()

This API should be used when user leaves the channel.
Calling this API will remove the user's channel contact list and all pending invitations that the user sent from this channel.
Therefore, contactLeft() will be called in BBMPlatformChannelListener on each of the contacts that was in the user's channel contact list.
However, pending incoming invitations, sent from other BBM contacts to the user, won't be removed,
which allows the user to re-join the channel in the future as long as the invitation hasn't expired.
The channel should not be used after the application calling destroy() on it.
Therefore, multiple calls of destroy() on the same channel object is not allowed.